Igniters are known in the prior art with a side vent on the metal case containing the pyrotechnic material, like that described for example in document WO2006045726A1. However, the side vent is generally made by a striking operation, which deforms the case and can subsequently cause problems with the plastic cap that covers the metal case to insulate it. Indeed, it may then be difficult to slip the plastic cap on the case due to variations in shapes and dimensions if the tolerance between the metal case and the cap is small. If, conversely, the tolerance between the metal case and the cap is more significant, liquid plastic may penetrate or infiltrate between the metal case and the cap and/or between the cap and the manufacturing mold during an overmolding operation. Quality and manufacturing problems then appear (appearance rejects, dimensional rejects and functional rejects, increased cycle times due to igniters blocked in the injection mold).
Document EP 1,489,376 A1 discloses an igniter with a case having a conical portion.